Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
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Switch: HRLNTXATZMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
956-637 A Rio Hondo TX 7421 AT&T - LOCAL 568      
956-637 9 Rio Hondo TX 7421 AT&T - LOCAL 568   2021-06-17   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

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